dostarlimab: clinical use

Prescribing considerations

• Initiate and supervise treatment through clinicians experienced in cancer therapy.
• Use validated tumour testing when dMMR/MSI-H status determines eligibility for monotherapy.
• Provide and explain the Patient Card, including possible delayed immune-related toxicity.
• Assess benefit and risk carefully in solid-organ transplant recipients and around allogeneic stem-cell transplantation.
• Use caution after a previous severe or life-threatening skin reaction to another immune-stimulatory anticancer treatment.
• Record the product name and batch number for biological traceability.

Contraindications and cautions

• Hypersensitivity to dostarlimab or any listed excipient.

Monitoring

• Assess for immune-mediated toxicity affecting any organ before, during and after treatment.
• Check haematology and clinical chemistry, including liver, kidney and thyroid function, at baseline and periodically.
• Investigate suspected pneumonitis with imaging and exclusion of alternative causes.
• Monitor during and after infusion for infusion-related reactions.
• Escalate suspected severe cutaneous adverse reactions promptly for specialist assessment.

Clinical pharmacology

Dostarlimab is a humanised IgG4 monoclonal antibody targeting PD-1. It blocks PD-1 binding to PD-L1 and PD-L2, restoring T-cell proliferation, cytokine production and cytotoxic activity. It is expected to be broken down into peptides and amino acids rather than metabolised through cytochrome P450 pathways.

Formulation and product differences

• The product is a sterile concentrate requiring dilution before intravenous infusion.
• It contains polysorbate 80, which may cause allergic reactions.
• The undiluted product is essentially sodium-free, although the infusion diluent may contain sodium.

Solution for infusion

Route: Intravenous

Strengths: 500 mg